In re Diamond Foods Inc. Derivative Litigation, C.A. 7657-CS (February 28, 2013)

Under the McWane doctrine, a Delaware court will dismiss  a case if another proceeding filed elsewhere is more advanced and will provide complete relief for any valid claim.  As this decision illustrates, while Delaware does not too often apply McWane, it will do so when it is the plaintiff in the Delaware litigation who has chosen to first seek relief in another state's court. The lesson is to not treat the Delaware court as your second choice.